# Barker Code Generator

Generate Barker Code

## Library

Sequence Generators sublibrary of Comm Sources

## Description

Barker codes, which are subsets of PN sequences, are commonly used for frame synchronization in digital communication systems. Barker codes have length at most 13 and have low correlation sidelobes. A correlation sidelobe is the correlation of a codeword with a time-shifted version of itself. The correlation sidelobe, Ck, for a k-symbol shift of an N-bit code sequence, {Xj}, is given by

${C}_{k}=\sum _{j=1}^{N-k}{X}_{j}{X}_{j+k}$

where Xj is an individual code symbol taking values +1 or -1 for j=1, 2, 3,..., N, and the adjacent symbols are assumed to be zero.

The Barker Code Generator block provides the codes listed in the following table:

Code lengthBarker Code
`1``[-1]`
`2``[-1 1];`
`3``[-1 -1 1]`
`4``[-1 -1 1 -1]`
`5``[-1 -1 -1 1 -1]`
`7``[-1 -1 -1 1 1 -1 1]`
`11``[-1 -1 -1 1 1 1 -1 1 1 -1 1]`
`13``[-1 -1 -1 -1 -1 1 1 -1 -1 1 -1 1 -1]`

## Dialog Box

Code length

The length of the Barker code.

Sample time

Period of each element of the output signal.

Frame-based outputs

Determines whether the block's output is frame-based or sample-based.

Samples per frame

The number of samples in a frame-based output signal. This field appears if you select Frame-based outputs.

Output data type

The output type of the block can be specified as an `int8` or `double`. By default, the block sets this to `double`.